German patent publication DE-197 54 078 discloses an airbag folding apparatus for producing airbag folds having a concertina-shaped profile. Here, the airbag conveys through a series of folding stations, each of which has moveable pairs of disks for folding the airbag. After the airbags leave the last folding station, the folds thus made are brought to bear against one another. A large number of machine elements makes the airbag folding process complicated and expensive.
Another German patent publication DE-195 35 564 discloses an airbag folding apparatus for folding an airbag by gathering the airbag toward a center using one or more slides. It can also include additional mechanical shaping elements for producing uniform folds. The entire airbag must rest on a flat surface, such as a base plate, and requires a cover plate, along with at least one slide and an associated drive mechanism.
In addition, for packaging a head airbag or side-window airbag, it is known to fold the airbag having a desired dimension (for example with the apparatuses described above) and then pull it into a flexible hose, or alternatively to fold it directly into a fixed housing. Here, the airbag likewise is folded using slides or knife folders. Accordingly, such an apparatus likewise is relatively costly.
In this respect, German patent publication DE 198 45 721 A1 describes a simpler apparatus for folding an airbag to a predetermined dimension. Here, the apparatus has a funnel-shaped member for squeezing or concentrating the airbag in the extended state. Once the funnel-shaped member compresses the airbag to a predetermined lateral dimension, the airbag is further compressed axially with a slide. The compressed airbag is then pushed out forcibly into a receptacle housing using the same slide. This apparatus requires a slide for axially pushing together the airbag and expelling it into a receptacle apparatus, and thus is relatively costly. The use of a slide also limits the speed of the folding of the airbag.
There still remains a need for improving the airbag folding apparatus and method without the disadvantages of these known airbag folding apparatuses. The present invention addresses this need.
The present invention relates to an apparatus for folding and packaging an airbag, and a method thereof.
One aspect of the present invention is an airbag folding apparatus includes a concentrator having an inlet and an outlet. The outlet has a smaller cross section so that the concentrator squeezes or compresses, i.e., folds, the airbag passing through the concentrator to a predetermined cross section. The concentrator is configured to reduce the dimension of the airbag by moving at least one of the airbag and concentrator relative to the other so that the airbag passes completely through the outlet. An area between the inlet and the outlet defines an airbag folding or compressing region or zone.
The inlet has a first cross section and the outlet has a second cross section that is smaller than the first cross section. The folded or compressed airbag thus exiting the outlet has a cross section substantially corresponding to the second cross section. The concentrator can be tapered at least along one plane so that the second cross section is smaller than the first cross section.
The concentrator can comprise a base plate and first and second concentrating elements mounted, spaced apart, on the base plate. The first concentrating element has a first cross section and the second concentrating element has a second cross section that is smaller than the first cross section. The concentrator can include at least one additional intermediary concentrating element secured to the base within the compressing region, between the first and second concentrating elements. The cross section of the additional concentrating element corresponds to the tapering profile of the concentrator. At least the first and second concentrating elements can have openings with a same height. The concentrating elements each can be U-shaped and secured to the base plate in an inverted configuration so that the base plate covers an open-end side of the U-shaped concentrating elements.
In another embodiment, the concentrator can comprise a base plate, a pair of concentrating elements mounted on the base plate, and a cover plate positioned over the concentrating elements so that the base and cover plates sandwich the concentrating elements. The height of the concentrating elements can define the height between the base and cover plates. The concentrating elements can comprise a pair of opposing side walls tapering toward the outlet.
At least the inlet and outlet can include pre-orientating elements for forming substantially uniform folds substantially along a longitudinal direction. In this respect, at least the first and second concentrating elements include pre-orienting elements for forming substantially uniform folds substantially along a longitudinal direction. In the alternative embodiment, at least the cover plate can include the pre-orienting elements for forming substantially uniform folds substantially along a longitudinal direction. The base plate also can include pre-orienting elements, which can be staggered relative to the pre-orienting elements of the first and second concentrating elements or the cover plate. The pre-orienting elements can comprise vertical webs or pins connected alternately to the base plate and the cover plate. In an alternative embodiment, the pre-orientating elements of the base plate or the pre-orienting elements of the cover plate or both can be retracted out of the compressing region.
These pre-orientating elements can form concertina-shaped folds substantially along the longitudinal direction.
Another aspect of the present invention is an airbag packaging apparatus, which can have all of the features of the above described airbag folding apparatus. The folding apparatus can be used for packaging the folded airbag into an airbag package. The folded airbag can be pulled into an airbag package as the folded airbag exits the outlet of the concentrator. The airbag package can be attached to the concentrator or held adjacent to it using any conventional means during that process.
The airbag package can have an inlet that has a cross section substantially corresponding to the outlet of the concentrator. The package can be elongate for side-window or head airbag. The length of the airbag package can correspond substantially to an extent of the airbag in the longitudinal direction. The package can further include lateral openings. The airbag can have a plurality of attachment tabs that align with the lateral openings when the airbag is fully inserted into the airbag package. The attachment tabs can be pulled through the lateral openings to expose them.
Another aspect of the invention is a method of folding an airbag, which can use the folding apparatus described above. In this respect, the method includes providing the concentrator and moving at least one of the airbag and concentrator relative to the other so that the airbag passes through the outlet to fold or compress the airbag to a predetermined cross section.
Another aspect of the invention is a method of packaging an airbag, which is substantially similar to the folding method described above. The package method includes additional steps of providing the afore-described airbag package and placing the inlet of the package adjacent to the outlet of the concentrator and moving at least one of the airbag and concentrator with the airbag package relative to the other so that the folded airbag exiting the concentrator is inserted into the airbag package.
The airbag can include a strap or the like at one end portion thereof. Pulling the strap through the concentrator and the airbag package while maintaining the concentrator at a fixed position pulls the airbag out of the concentrator and into the airbag package. Alternatively, the strap can be fixed to a stationary element. Moving the concentrator and the airbag package relative to the airbag so that strap becomes exposed through the airbag package also pulls the airbag out of the concentrator and into the airbag package.
The method can further include the step of pulling out the attachment tabs through the lateral openings after the airbag has been inserted into the airbag package.
Pulling the airbag through the concentrator having the pre-orienting elements substantially forms uniform folds.